The general construction of biomedical electrodes of this general type is described in detail in U.S. Pat. No. 3,862,633, issued Jan. 28, 1975, to Kenneth C. Allison and William H. Cooley. The biomedical electrode disclosed in the aforementioned patent is satisfactory for many purposes. In making certain observations, it is particularly desirable to provide a biomedical electrode which utilizes a silver-silver chloride half cell. Silver is expensive; and is to be used sparingly in a disposable biomedical electrode.
Another problem encountered with biomedical electrodes of this general type is that it is often desirable to provide a means for holding the diaphragm outward from the container. During usage, there is a gradual outflow of electrolyte, thereby reducing the volume of electrolyte, which allows the diaphragm to bow inward slightly of the container. Contact between the diaphragm and the surface of the subject may be impaired when the diaphragm bows inward. Furthermore, many practitioners find that they would like to observe the interior of the electrode while applied to a subject, especially after prolonged use.